Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 60 for “"Catch rates"”.
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Seasonal and lunar trends in catch rates of sharks caught in the protective gill nets off KwaZulu-Natal, South Africa
A retrospective statistical analysis of catch and effort data for sharks captured in protective gill nets along the KwaZulu-Natal coastline was carried out with the objective to establish if the frequency of shark catches is related to different phases of the moon and secondly to season.
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The Response of a Predatory Fish, Ophiodon elongatus, to a Marine Protected Area: Variation in Diet, Catch Rates, and Size Composition
<p>Marine Protected Areas (MPAs) are a management tool used to protect and sustain many ecologically and economically important fish species from overexploitation by recreational and commercial fishing. Lingcod (<em>Ophiodon elongatus</em>) and some of its prey species, such as rockfish …
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An investigation of spatial-temporal diel changes in Loligo reynaudii catch rates in the commercial squid jig fishery of South Africa
… the year. Considering that commercial jig catches similarly depend on the prevalence, intensity and duration of aggregations; and assuming standardised Catch Per Unit Effort (CPUE) to be a representative measure of local abundance and proportional representation of regional population …
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A comparative study on the fish species composition, diversity and catch rates among the fisheries reserves on the Zambezi and Kwando rivers, Zambezi region
… specifically species composition, diversity, and catch per unit effort (CPUE); across five fisheries reserves located along the Zambezi River (Sitwela, Kabweza, and Makangala) and the Kwando River (Luhingi and Qhuqhumupa). Gillnet surveys using both experimental and monofilament gillnets were …
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Evaluating Alberta’s Fall Index Netting Protocol for Assessing Northern Pike (Esox lucius) Populations
… we tested five hypotheses relating FIN catches to independently measured abundance and sizes of Northern Pike, including testing the economic effectiveness of FIN monitoring. These tests used fisheries survey data on 133 lakes collected between 2000 and 2020. Mark-recapture studies and …
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Effects of fishing on a coral reef fish assemblage in Northeastern Brazil
… generally lacked detailed information on the catch and effort by gear and habitat type. In this dissertation, the sustainability of a coral reef fishery at the Marine Protected Area Costa dos Corais, Northeastern Brazil is assessed. In 1,833 landing interviews with local fishers, 100 fished …
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Evaluation of Smallmouth Bass Introductions in South Dakota Lakes
… paired mean electrofishing and mean fyke net catch rates among lakes, both for stock- length (18 cm) fish (r=0.973, P=0.005) and all fish ( r = 0.948, P=0.014). These correlations suggest that both gears were not seriously affected by environmental conditions within the ranges encountered. An …
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Characterizing a Hidden Fishery: Setline Fishing in the New River, Virginia
… setline fishery by estimating setline effort and catch rates of catfish and by-catch in 2011, and by investigating the attitudes and opinions of setline users during 2012. Setline effort was highest during June-August, and declined significantly by mid-September. Several dedicated setline users …
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Population/Biomass Estimates and Relative Abundance Indices of Adult Common Carp in Arrowwood and Sand Lake National Wildlife Refuges
Fish catch rates in passive gear, such as gill nets, are commonly used by biologists to index fish population density. The purpose of this project was to assess the potential relationship between common carp (Cyprinus carpio) biomass and catch-per-unit-effort (CPUE) in gill nets. Adult common carp …
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Assessment of patterns in the Namibian hake fishery based on commercial fisheries data, in relation to environmental factors
… processes. The influence of various factors on catch rates (CPUE) is investigated using a general linear model.
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SCAPHIRHYNCHUS STURGEON EARLY-LIFE HISTORY
… features used. Age-0 Scaphirhynchus sturgeon catch rates were highest around artificial structures (i.e., wing dikes) and island areas while main channel habitat comprised the lowest catch rates. Within these habitats, young sturgeon frequently occupied low velocities (i.e., ~0.1), moderate …
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Assessment of bycatch species in the Namibia Hake directed bottom trawl fishery (1997-2014)
… management, is how to manage and mitigate bycatch caught during commercial fishing. The Namibian hake-directed bottom trawl fishery has been an important component of the Namibian fishing industry for decades. Due to the low selectivity of the bottom trawling method, bycatch has been a common …
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Observer effects on pelagic fleet operations and Bayesian-based explorations of the mass balance model ECOPATH
… are thought to arise, inter alia, from large bycatches of sardine (counting against a bycatch allowance) with anchovy and unsuitable sizes of sardine caught for canning purposes. As there were no data that could be used as a basis to investigate the claims, little was done to substantiate them. …
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Evaluation of Brook Trout (Salvelinus fontinalis) Introductions and Re-introductions Into Four Virginia Blue Ridge Mountain Streams
… streams almost three years post introductions. Catches decreased across the first four surveys. Young of year catch rates severely decreased from June 2009 (n = 77) to June 2010 (n = 7). Adult refuge under low flow conditions and environmental factors such as elevated stream temperatures and …
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Habitat utilization and movement patterns of subadult largemouth bass (Micropterus salmoides) in the Ohio River
… macrohabitat of subadult largemouth bass. Catch rates within macrohabitats were low ranging from 0.00--2.73 subadult bass/hour. Embayment electrofishing CPUE was higher than tributary or main channel except in spring, when tributary CPUE was highest.;Core use areas were calculated from …
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Geostatistical spatiotemporal modelling with application to the western king prawn of the Shark Bay managed prawn fishery
… However, fishery-dependent commercial catch and effort data, throughout each season, are available for many fisheries as part of the ongoing monitoring program to support their stock assessment and fishery management. An example of such data is prawn catch and effort data from the Shark …
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Results and Evaluation of An Aerial Creel Survey Technique On Lake Sharpe, South Dakota
… an angler interview survey was used to estimate catch rates, mean party size, mean fisherman day, and residence of the anglers. The results of the two surveys were combined to estimate harvest. The separate surveys were combined to estimate harvest. The separate surveys allowed optimum …
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Potential of a trap-fishery for the spiny lobster Palinurus delagoae off eastern South Africa : has the stock recovered?
… observers were used to explore fishing effort, catches and catch per unit effort. The recent data were compared with those for a previous experiment conducted in 1994-1997, which apparently contributed to the collapse of the stock, to determine whether the stock had recovered and could sustain a …
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Fish species composition, fish sizes and diversity in the Kamutjonga floodplain, Kavango river, Namibia
… 2017, 1678 fishes in 2018 and 4461 in 2020. The catch per unit effort (CPUE) by number was higher in 2017, followed by 2018 and lastly 2020. 31 fish species from 10 families, 37 species from 11 families and 31 species from 9 families were identified in 2017, 2018 and 2020 respectively. The …
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Preying on the predator : the shark fin controversy
… both the market for shark fins and global catch rates have continued unabated. If the demand for fins and the practice of shark finning continue at the current rate, human interference may forever change the nature of our oceans.
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